02/01/2012 Example Java XPath parsing and setting using org.dom2 http://www.jdom.org/

Main.java

import java.io.*;
import org.jdom2.*;
import org.jdom2.filter.Filters;
import org.jdom2.input.*;
import org.jdom2.output.XMLOutputter;
import org.jdom2.xpath.XPathExpression;
import org.jdom2.xpath.XPathFactory;
import java.io.File;
import java.util.List;
import java.util.*;


public class Main {
    private static void log(String aMessage) {
        System.out.println(aMessage);
    }

    public static void main(String[] args) throws Exception {

        for (String country_code : Arrays.asList(new String[]{"AU", "BE", "CA", "DE", "DK", "ES", "FI", "FR", "GB", "IE", "IT", "JP", "NL", "NO", "NZ", "SE", "US"})) {
            try {

                SAXBuilder saxBuilder = new SAXBuilder();
                Document doc_channel = saxBuilder.build(new FileReader("C:\\temp\\xmlp\\countries\\" + country_code + "\\channel-sets-" + country_code + ".xml"));
                Document doc_cat = saxBuilder.build(new FileReader("C:\\temp\\xmlp\\countries\\" + country_code + "\\category-set-" + country_code + ".xml"));

                XPathExpression<Element> xp_channel = XPathFactory.instance().compile("//channels/channel[@access='PREMIUM']", Filters.element());
                List<Element> channel_elements = xp_channel.evaluate(doc_channel);

                for (Element channel_emt : channel_elements) {
                    log("Channel Element GUID " + channel_emt.getChild("tracks").getAttributeValue("guid") + " " + channel_emt.getName());
                    String chn_code = channel_emt.getAttribute("code").getValue();
                    if (chn_code.contentEquals("indie-rock-and-alternative-top-100")) {
                        log(" Change Channel Code set: " + chn_code);
                        chn_code = "indie-rock--alternative-top-100";
                    }

                    XPathExpression<Element> xp_category = XPathFactory.instance().compile(".//categories/category[@code='" + chn_code + "']", Filters.element());
                    List<Element> category_elemets = xp_category.evaluate(doc_cat);
                    for (Element cat_emt : category_elemets) {
                        for (Element target : cat_emt.getChildren("tracks")) {
                            //if (target.getAttributeValue("guid") == "") {
                            //log("Blank GUID " + target.getAttributeValue("guid"));
                            target.setAttribute("guid", channel_emt.getChild("tracks").getAttributeValue("guid"));
                            XMLOutputter xout = new XMLOutputter();
                            xout.output(doc_cat, new FileOutputStream(new File("C:\\temp\\xmlp\\done\\" + country_code + "\\category-set-" + country_code + ".xml")));
                            //}
                        }
                    }
                }

            } catch (Exception e) {
                log(e.toString());
            }
        }


    }
}